Trip Report: An Introduction to Caving in Ogof Clogwyn

Petra wanted to join us for an introduction to Welsh caving (each cave region has its own 'feel' you see, and Petra was used to the large showcaves of Slovakia) and to cover some technical caving skills; so we designed a day for her using the caves beneath Gilwern Hill and Clydach Gorge.

Our day began with a little nose into a very small coal-mine that locals had dug during the Miner's Strikes of the 1980's in order to keep their homes and families warm. It was a very well-hidden entrance, having lain pretty much undisturbed for the last 30 years, leading to a really interesting section of carefully constructed supporting pillars and walls and then to a glistening black coal seam. It was really quite humbling to lay in the same space that the original miners had done, imaging them swinging their mandrel (a sort of coal-miners pick-axe) and digging into the coal, just as so many generations of miners have done in these hills for hundreds of years before them.

​From here we made the short journey across Gilwern Hill to find Ogof Clogwyn, a pretty straightforward cave popular with novices, school groups and even military personnel. Descending along the footpath, through bronze beech leaves littering the forest floor, it was hard not to be moved by the sheer beauty of the ancient gorge, with the river Clydach cascading along the gorge beneath us. The cave entrance is an obvious gap in a cliff of pale limestone but, a small stream running out of the darkness and pouring off a 5 foot high ledge does set the price for exploring it; f you are prepared to climb up onto this ledge and into the cave (risking a wet welly in the stream) then the whole caving adventure is secured.

The waterfall ledge is part of the solid bedrock of the cave but also helps to show how the cave was formed in the first place (first as a small tube of high pressure water eroding the rock, and later as slower moving water eroding downwards to create a 'keyhole' shape). We followed the passage on hands and knees for a few metres before it opened up into a full-walking-height passageway and from here we began to explore the small offshoot passages as well as making an obstacle course of the geological features such as the rock shelving, oxbow passages and passageways running above our heads and below our feet.

The cave is basically a long tube which follows a streamway as it meanders inside the limestone cliff, however, there is an upper series which runs as a second, smaller, tube above your head as well as there being a number of smaller windows and exits that can be explored and negotiated as the desire for challenge grabs you.

About halfway through the cave we paused at a large boulder to look at some of the ropework and knots that we can use to safeguard people when dealing with short climbs or descents within the cave. After demonstrating a hand-line and traverse-line we spent some time exploring the knots and process used to create these rope systems before coaching Petra through building them herself.

Moving on from the boulder we explored to the fossil chamber and then on to the point where the cave roof dips down to meet the stream and the cave ends as a sump. The challenge and adventure isn't over just yet though as we then explored the passageway to find a small offshoot that leads down to some more sandy passage and pots that can be climbed into. Happy that we had completed the whole length of the cave we then began our journey back, splashing through the knee-deep water, climbing up onto ledges, hopping carefully from shelf to shelf and finally arriving back at the waterfall entrance to the cave.

Enough of me writing though, why not make yourself a cup of tea and watch some of our cave adventures in Ogof Clogwyn on YouTube instead: